A small breakdown.
Cryptocurrency is just as the name implies. Encrypted currency. Lines of code which can be traded as fiat money.
The difference? The worth, philosophy and set up.

Fiat money is backed through gold and/or silver reserves. Worth depends on how much money is in circulation in combination with the amount of gold/silver that backs it up. To illustrate: your mom has made one pie for the entire family. You and your siblings get notes on how much pieces of pie you are entitled to. All notes together equal the pie as a whole. If your mother bakes a second pie with which you can use the notes (or some notes are lost), the notes increase in value. If new notes are made or if the original pie is cut in half the notes decrease in value. Your mother, as pie-maker, can be seen as the caretaker of value. She checks and holds the notes while at the same time controls the value behind them.

Cryptecurrency is not backed by gold or silver. Instead its value depends on securized transactions. The encrypted currency itself is nothing more than a line that reads "TIME OF CREATION (YY/MM/DD/HH/Min/Sec)- time of transfer (YY/MM/DD/HH/Min/Sec)" (or something along these lines). Each time it is traded this line becomes bigger ("time of transfer (YY/MM/DD/HH/Min/Sec)" is added each time) . This is a block. Naturally, new blocks can be made by adding a new line of code to the network (hence the name "blockchain"). In order for the currency to have value it MUST be traded AND the trade verified by everyone in the network (called mining). This gives rise to a currency with very fluctuating value but is EXTREMLY high secured. Due to lack of a centralized authority, the currency itself becomes valuable over time. Deviations can occur when the 51% rule is applied (the moment more than 51% of the network invalidates the transaction). Due to the majority vote will that line be followed and the transaction negated. The block itself will live on in a sort of limbo. This gives rise to a new blockchain and alternate Cryptocurrency which follows the initial setting of the original blockchain. This is very unlikely to occur by reason validation is either 100% or not. The 51% is only attained through corrupted mining whereby the processing power of the miner exceeds 51% above the network.... which can only occur in the initial stages of the blockchain (which is also extremly unlikely considering the costs vs actual gain).

Where does all the hype come from? What is to gain?
Due to the nature of cryptocurrency, it is higly sought after on the dark web. You can make anonymous transactions as only the transaction is verified BUT NEVER THE OWNERS. That information is encrypted in such a way only the current owner knows he has the currency. No one else does know who has the cryptocurrency UNLESS the owner makes it known.

Apart from the anonymous transactions it also is to be considered as an international currency that has the same value WORLDWIDE. 1 coin has the same value EVERYWHERE. The guy in India can rest assured that his 1 coin is of equal worth at home as well as in Australia, China, The USA, Canada and Europe. There are no exchange rates whatsoever.

The hype is philosophical. Due to decentralization and the peer-to-peer verification across the entire network (and extremely high security that it entails) gives cryptocurrency the ability to almost be incorruptable. Inflation and deflation through centralized means CANNOT occur. Due to its nature things such as Zimbabwe's, Greece's, Peru's,... hyperinflation are impossible. Indeed, some countries are looking into the possibility to utilize a form of cryptocurrency as their national fiat.

There are gains to be made. Like wallstreet you can invest in cryptocurrency. Prices vary/fluctuate due to the aforementioned amount of transactions taking place. It becomes an art to predict when to buy and when to sell. You only need to predict "when" most transactions will occur and cipher in the possibility that as value rises it may also encounter a sudden steep decline if the network holds on to the currency when value is on its highest. Cryptocurrency NEEDS TO BE TRADED in order to have high value.

What are my thoughts?
I'd say it is wise to invest and get onto that caroussel. Many websites accept bitcoin which enables you to buy goods against a fairer price and without bias. It holds potential to become the preferred method of payment online due to its high security and incorruptable nature. As a replacement for fiat money.... not so much. It holds the potential and the means to do so... but I can assure a strict and irrevokable hyperinflation to the economy if it were to occur due to its nature. It is a currency which DEFINES and is in line with Capitalism. Value through spending. Not a something you can hang on to as a reserve to buy a house or car later on as the action of not spending it devalues the currency as a whole.

What are your thoughts?
Ut vivat, crescat et floreat